土石坝动力参数反演分析

Inverse Analysis on Dynamic Parameters of Earth-rock Dam

对土石坝进行抗震安全评价时,确定土体动力参数是至关重要的;传统的土体参数是通过现场试验或室内试验确定,但是受试验方法、设备以及设计变更、现场施工等影响,很难符合实际土体的动力特性。本文利用基于浮点编码的遗传算法与有限元计算理论,建立了土石坝动力参数的反演方法;通过有限个测点在地震过程中的加速度响应反演出真实的土体动力参数、以及最大阻尼比。数值算例表明,这种方法具有很好的参数识别精度,在工程中具有较大的应用价值。

Determination of the dynamic soil parameters is very important in seismic safety evaluation of earth-rock dams.The traditional soil parameters are determined by field test or laboratory test.But actually it is hard to accord with the real dynamic characteristics of soil owing to limitation of test method, test instrument and site construction.In this paper,inversion method of the dynamic parameters of earth-rock dams is established using genetic algorithm based on the floating-point coding and theory of finite element.The real soil parameters,and the maximum damping ratio is inversed according to acceleration responses of limited measuring points in the process of earthquake.Numerical examples show that this method has good accuracy of parameter identification and great application value in engineering.